Light-metal strip wheel

ABSTRACT

A light-metal strip wheel, in particular for motor vehicles, which includes a wheel disk and a rim. The wheel disk comprises two wheel-disk parts each having a ventilation hole. The ventilation holes have necks that when pressed into one another, secure together the two wheel-disk parts with the two parts separated from one another in the region surrounding the ventilation holes, while coming to rest on one another in a hub region. The space between the two wheel-disk parts in the region surrounding the ventilation holes increases the stiffness of the strip wheel so that the wheel is suitable for accommodating large loads.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light-metal strip wheel, inparticular for motor vehicles. An application of the light-metal stripwheel in accordance with the invention is for a vehicle in whichdisposed around the light-metal strip wheel is a tire.

2. Description of the Related Art

A conventional light-metal strip wheel is described in German patentpublication DE-OS 33 28 135. In order to avoid welded connections, thisstrip wheel is composed of a plurality of sheet blanks connected in apositive locking fashion to form a rim with rim flanges and a wheeldisk. Edge regions of the wheel disk are held in the rim flanges bymeans of clinching. This design has the disadvantage of beinginsufficiently stiff and therefore is suitable only for medium loads.Furthermore, the clinching process necessitates a large number ofmanufacturing steps.

A similar vehicle wheel is described in German patent publication DE-AS24 23 181. This vehicle wheel has a double-walled wheel disk and aflat-base rim connected thereto. The two wheel-disk walls are connectedto one another. The inner rim part is formed by one wall and the outerrim part is formed by the other wall. The double-walled wheel disk hasventilation holes, and the two wheel parts are connected to one anotherby means of hole riveting at the ventilation holes.

It is desirable to develop a light-metal strip wheel having sufficientstiffness so that it can accommodate large loads and yet simple tomanufacture.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a substantiallylight-metal strip wheel which is lightweight, stiff and simple tomanufacture.

In accordance with the invention a light-metal strip wheel, inparticular for motor vehicles, includes a wheel disk and rim. The wheeldisk comprises two wheel-disk parts each having a ventilation hole. Theventilation holes have necks that, when pressed into one another, securetogether the two wheel-disk parts with the two wheel-disk partsseparated from one another in the region surrounding the ventilationholes, while coming to rest upon one another in the hub region. Thespacing between the two wheel-disk parts in the region surrounding theventilation holes increases the stiffness so that the strip wheel issuitable for accommodating large loads.

The light-metal wheel design is advantageous in that it is lighter thanconventional light-metal wheels because the two wheel-disk parts do notrequire the use of sheet-metal having a large or significant thickness.In addition, even though the wheel is lighter in weight, it possessessufficiently high stiffness for sustaining or accommodating large loads.

Other objects and features of the present invention will become apparentfrom the following detailed description considered in conjunction withthe accompanying drawings. It is to be understood, however, that thedrawings are designed solely for purposes of illustration and not as adefinition of the limits of the invention, for which reference should bemade to the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein like reference numerals denote similar elementsthroughout the several views:

FIGS. 1a& 1b depicts respective cross-sectional views of a wheel-diskouter part and a wheel-disk inner part, in the unassembled state, inaccordance with the invention;

FIG. 2 depicts a cross-sectional view of the two wheel-disk parts ofFIGS. 1a& 1b, in the assembled state, in accordance with the invention;

FIG. 3 depicts a cross-sectional view of the assembled two wheel-diskparts of FIG. 2, including the attachment hole and axis guide hole, inaccordance with the invention;

FIG. 4 depicts a cross-sectional view of an assembled wheel including awheel disk and a rim, in accordance with the invention;

FIGS. 5a & 5b show cross-sectional views of an alternate embodiment of awheel-disk outer part and a wheel-disk inner part, in the unassembledstate, in accordance with the invention; and

FIG. 6 is a cross-sectional view of the two wheel-disk parts of FIGS. 5a& b, in an assembled state, in accordance with the invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

A wheel disk constructed in accordance with the present invention isformed of two wheel-disk parts 1,2, as respectively shown in FIGS. 1a&1b. Wheel-disk part 1 represents a wheel-disk outer part and the otherwheel-disk part 2 represents a wheel-disk inner part. Each wheel-diskpart 1,2 is formed or fabricated of a substantially light-metal stripmaterial, preferably aluminum. Each wheel-disk part 1,2 includes arespective neck 5,6 extending therethrough toward the inside of thewheel and thereby defining respective ventilation holes 3,4. The neck 5has an inner surface 5a facing the ventilation hole 3 and an outersurface 5b. The neck 6 has an inner surface 6a facing the ventilationhole 4 and an outer surface 6b. In order to ensure that the twowheel-disk parts 1,2 will fit together to form a wheel disk, a maximumouter diameter "da" of neck 5 of wheel-disk part 1 is selected so thatit is equal to or smaller than an inner diameter "di" of neck 6 ofwheel-disk part 2. The wheel disk is assembled by inserting the neck 5into the ventilation hole 4 so that a press fit engagement is providedand forms in a region between the outer surface 5b of neck 5 and theinner surface 6a of 6.

Each wheel-disk part 1, 2 includes another respective neck 20, 21 whichalso extends toward the inside of the wheel along the outermostcircumference of each wheel-disk part 1, 2. Each neck 20, 21 has aninner surface 20a, 21a and an outer surface 20b, 21b, respectively. Whenthe wheel-disk parts 1, 2 are assembled, the outer surface 21b contactsthe inner surface 20a of neck 20. Inner surfaces 5a, 6a, 20a, and 21aand outer surfaces 5b, 6b, 20b, and 21b are substantially axial indirection.

FIG. 2 shows the two wheel-disk parts 1,2 in the assembled state. Priorto assembly, adhesive may be applied to one or both parts in the regionof the press fit to ensure that the two wheel-disk parts 1,2 remainassembled. Once assembled, the two wheel-disk parts 1,2 are separated bya space 7 defined in a region surrounding the ventilation hole 3 and arein contact with one another in the hub region. The presence of the space7 of the wheel design in accordance with the invention is advantageousin that it significantly contributes to the stiffness of the wheel, sothat the wheel is capable of sustaining or accommodating larger loadsthan would otherwise be possible.

FIG. 3 shows the assembled wheel disk 11, comprising the engagedwheel-disk outer part 1 and wheel-disk inner part 2, after attachmenthole 8 and axis guide hole 9 have been created in the hub region, as forexample by stamping. When so stamping out the attachment hole 8, astamping 10 is created extending outwardly therefrom. Stamping 10provides the additional benefit of absorbing high surface pressures inthe region of the attachment hole 8.

As illustrated in FIG. 4, the assembled wheel disk 11 is materiallyconnected, as for example welded via a welded seam 13, to a rim 12. Inan alternative modification or embodiment, adhesive may be appliedbetween the wheel disk 11 and the rim 12 and hardened, as for exampleduring stove enamel processing. Instead of or in addition to using anadhesive, the wheel disk 11 may be soldered to the rim 12. In accordancewith this embodiment the two wheel-disk parts 1,2 and rim 12 are formedof partially solder-plated starting materials. Preferably, the rim 12and the wheel-disk inner part 2 are formed of an AlMgSi strip plated onone side, and the wheel-disk outer part 1 of an unplated AlMgSi strip,or the wheel-disk outer part 1 may be formed of an AlMgSi strip platedon both sides and the rim 12 and wheel-disk inner part 2 of an unplatedAlMgSi strip. When using partially plated AlMgSi strips for the rim andwheel-disk parts, the preferred plating material comprises X AlSi 10.However, other types of strips and plating material may also be used.

An alternate arrangement of the wheel-disk inner part is illustrated inFIGS. 5a, 5b. In contrast to FIG. 1b in which the necks 5 and 6 arearranged so that they face in the same direction (i.e. towards theinside of the wheel), in FIG. 5b the necks 5, 6 are positionedconfrontingly opposite to one another. Thus, with the arrangement shownin FIG. 5b the hub region of the wheel-disk inner part 14 extends closerto the outside of the wheel than the hub region of the wheel-disk innerpart 2 in the configuration shown in FIG. 1b. As in the embodimentsdescribed earlier herein, the two wheel-disk parts 1, 14 definetherebetween a space 15 after assembly, as shown in FIG. 6. Thismodified arrangement provides an additional advantage over theconfiguration shown in FIG. 1b. Instead of, or in addition to, using anadhesive applied to the region between the necks 5,6, the two wheel-diskparts 1,2 may be connected to one another in a positive-locking mannersuch as by clinching, crimping or otherwise deforming the end of theneck 5 and 20 to form an end regions 16. All other aspects of thestructure and invention previously described with respect to theembodiment shown in FIGS. 1a, 1b are also applicable to this modifiedembodiment.

Manufacture of a light-metal strip wheel, in accordance with theinvention, begins by drawing a plurality of sheet blanks through amultiple die press multiple times to create the wheel-disk outer part 1and the wheel disk inner part 2, with each wheel-disk part 1,2 having arespective neck 5,6 which defines a ventilation hole 3,4. The wheel-diskouter part 1 and the wheel-disk inner part 2 are then assembled bypressing the two disk parts together in a region surrounding each of thenecks 5,6. In an alternate embodiment, prior to pressing the twowheel-disk parts together, adhesive may be applied to the necks 5,6 inthe region of contact therebetween. Thereafter, the two wheel-disk parts1,2 are redrawn to form a press fit in the region of the necks 5,6 withthe two wheel-disk parts 1,2 separated by a space 7 in the regionsurrounding the necks 5,6 and in contact with one another in the hubregion.

Wheel disk 11, comprising the assembled two wheel-disk parts 1,2, isthen stamped in the hub region to thereby create the attachment hole 8with the stamping 10 extending outwardly therefrom, and the axis guidehole 9. Next, the wheel disk 11 is pressed into and materially connectedto the rim 12 to form the wheel. Rim 12 may be welded via a welding seam13, as shown in FIG. 4, to the assembled wheel disk 11. Alternatively,the two wheel-disk parts 1,2 and rim 12 may be formed of partiallysolder-plated starting materials, as discussed above, and the wheelparts and rim soldered together in a vacuum oven and then cooled.Furthermore, in accordance with the wheel-disk arrangement illustratedin FIG. 6, the processing may include the additional step of clinchingthe end of the neck 5 and 20 of the wheel-disk outer part 1 to form endregion 16.

Finish processing of the wheel includes stove enamel processing of theouter surface of the wheel and working the visible surface of the wheelsuch as by shot peening. The soldering and stove enamel processing ofthe wheel may be carried out in the framework of a total heat treatmentin order to further increase the strength of the material. Any otherknown or appropriate finish processing steps are likewise within theintended scope of the invention.

Thus, while there have shown and described and pointed out fundamentalnovel features of the invention as applied to preferred embodimentsthereof, it will be understood that various omissions and substitutionsand changes in the form and details of the devices illustrated, and intheir operation, may be made by those skilled in the art withoutdeparting from the spirit of the invention. For example, it is expresslyintended that all combinations of those elements and/or method stepswhich perform substantially the same function in substantially the sameway to achieve the same results are within the scope of the invention.It is the intention, therefore, to be limited only as indicated by thescope of the claims appended hereto.

We claim:
 1. A substantially light-metal strip wheel, comprising:a wheeldisk including an axially-defined guide hole, a hub region defined aboutsaid guide hole, and an attachment hole defined in and through saidwheel disk in said hub region, said wheel disk comprising a firstwheel-disk part and a second wheel-disk part each having a firstsubstantially axially extending neck boundingly defining a ventilationopening in each said first and second wheel-disk parts and a secondsubstantially axially extending neck positioned at an outermostcircumference of each said first and second wheel disk parts, said firstand second wheel disk parts being configured to be pressed together sothat when said first and second wheel-disk parts are pressed together inneck-to-neck contact to form said wheel disk, said first and secondwheel-disk parts are predeterminately spaced apart in a directionsubstantially perpendicular to a plane of said wheel proximate saidventilation openings and abut one another proximate said hub region,wherein said first substantially axially extending necks of said firstand second wheel disks contact each other along axially extendingcontact surfaces and said second substantially axially extending necksof said first and second wheel disks contact each other along axiallyextending contact surfaces; and a rim connected to said wheel disk forforming said strip wheel.
 2. The substantially light-metal strip wheelof claim 1, wherein said ventilation opening is defined in each saidwheel-disk part radially-outwardly from said hub region.
 3. Thesubstantially light-metal strip wheel of claim 2, wherein saidwheel-disk parts comprise a wheel-disk inner part and a wheel-disk outerpart.
 4. The substantially light-metal strip wheel of claim 3, whereinan end of said neck of the wheel-disk outer part is clinched around thewheel-disk inner part.
 5. The substantially light-metal strip wheel ofclaim 3, further comprising a stamping extending outwardly from at leastone of said wheel-disk parts at said attachment hole.
 6. Thesubstantially light-metal strip wheel of claim 3, wherein saidwheel-disk parts and said rim comprise partially solder-plated startingmaterials.
 7. The substantially light-metal strip wheel of claim 6,wherein each of the rim and the wheel-disk inner part comprise an AlMgSistrip plated on one side, and the wheel-disk outer part comprises anunplated AlMgSi strip.
 8. The substantially light-metal strip wheel ofclaim 6, wherein the wheel-disk outer part comprises an AlMgSi stripplated on both sides and each of the rim and the wheel-disk inner partcomprises an unplated AlMgSi strip.
 9. The substantially light-metalstrip wheel of claim 7, wherein the plating comprises X AlSi 10material.
 10. The substantially light-metal strip wheel of claim 8,wherein the plating comprises X AlSi 10 material.
 11. The substantiallylight-metal strip wheel of claim 3, wherein an outer diameter of theneck of the wheel-disk outer part is at least no greater than an innerdiameter of the neck of the wheel-disk inner part.
 12. A substantiallylight-metal strip wheel, comprising:a wheel disk including oneaxially-defined guide hole, a hub region defined about said guide hole,and a plurality of attachment holes defined in and through said wheeldisk in said hub region, said wheel disk comprising a wheel-disk innerpart and a wheel-disk outer part each having a first substantiallyaxially extending neck boundingly defining a ventilation openingradially-outwardly from said hub region in each said inner and outerwheel-disk parts and a second substantially axially extending neckpositioned at an outermost circumference of each said inner and outerwheel disk parts, said inner and outer wheel disk parts being configuredto be pressed together so that when said inner and outer wheel-diskparts are pressed together in neck-to-neck contact to form said wheeldisk, said inner and outer wheel-disk parts are predeterminately spacedapart in a direction substantially perpendicular to a plane of saidwheel proximate said ventilation openings and abut one another proximatesaid hub region, wherein said first substantially axially extendingnecks of said inner and outer wheel disks contact each other alongaxially extending contact surfaces and said second substantially axiallyextending necks of said inner and outer wheel disks contact each otheralong axially extending contact surfaces; and a unitary rim connected tosaid wheel disk by one of an adhesive material, a soldering material anda welding material.
 13. A substantially light-metal strip wheel,comprising:a wheel disk including an axially-defined guide hole, a hubregion defined about said guide hole, and an attachment hole defined inand through said wheel disk in said hub region, said wheel diskcomprising a first wheel-disk part and a second wheel-disk part eachhaving a first substantially axially extending neck having a first innersurface boundingly defining a ventilation opening in said eachwheel-disk part and a first outer surface facing away from saidventilation opening and a second substantially axially extending neckpositioned at an outermost circumference of each said first and secondwheel disk parts having a second inner surface facing radially inwardand a second outer surface facing radially outward, said first andsecond wheel disk parts being configured to be pressed together so thatwhen said first and second wheel-disk parts are pressed together inneck-to-neck contact to form said wheel disk, said first and secondwheel-disk parts are predeterminately spaced apart in a directionsubstantially perpendicular to a plane of said wheel proximate saidventilation openings and abut one another proximate said hub region,said first inner surface of said first wheel disk contacting said firstouter surface of said second wheel disk and said second outer surface ofsaid first wheel disk contacting the second inner surface of said secondwheel disk; and a rim connected to said wheel disk for forming saidstrip wheel.